Treating paper-stock



STATES Areivr mace.

HENRY GARMIGHAEL, OF BRUNSWICK, MAINE.

TREATING PAPER-STOCK.

. SPECIFICATION forming part of Letters Patent No. 267,492, dated November 14, 1882.

Application filed March 18, 1882. (Specimens) all whom it may concern:

Be it known that I, HENRY GARMIOHAEL, ofBrunswick, in the county ofOumberland and State of Maine, have invented a new and usefullmprovementin Treating Paper-Stock; and I do hereby declare that the followingis afull, clear, and exact description of the same.

My invention is an improvement in articles made of paper or paper-stock-such as paperboard boxes, basins, pails, lamps, and like vesselsand in the process of making the same, or

of rendering the material hard, capable ofpolish, and proof against the action of water, oils,

mild alkalies, and other agencies to which such paper vessels or receptacles are exposed, and by which they are liable to injury when in common use.

It is well known that many vessels and re: ceptacles of various kinds and forms are now made of paper, or of ordinarypaper orlike pulp. Such articles have heretofore been strengthened and waterproofed in various ways by saturation with various substances, but principally by surface coating of paint or like covering. In all of these the sole object and effact have been to exclude the water or other liquid to which the surfaces were exposed. My object is to improve such articles as the above specified in respect to hardness, strength, capability of polish, and also to render said'articles impermeable to all that class of liquids to contact with which they are ordinarily subjected.

To this end my process consists in saturat= ing the aforesaid paper or paper-pulp articles with boiled linseed-oil, or linseed-oil thickened by the known process of agitation in the presence of light and air, and in subjecting the articles so saturated to a high degree of heat, all as hereinafter specified. I prepare the linseedoil by boiling or by agitation, as aforesaid, until by the escape cf the more volatile constituents and by-a greater or less extent of oxidation the oil is reduced to a thick semi-liquid mass, which, at ordinary temperature, is of the consistency of cold molasses. Into the oil brought to this condition I immerse the paper or paper-pulp article, whether it be a lamp, lamp-cup, basin, pail, or any other of the articles made or which may be made of paper or paper-pulp, said article having first been heated to the highest degree to which it may safely be subjected. This is usually about .270 of Fahrenheit. The oil is kept at the same temperature, or somewhat higher. The article is allowed to remain in the oil a length of time dependent upon thethickness and porosity of the walls or parts thereof; but in no case is it permitted to absorb more ofthe oil than by the subsequent treatment may be converted into a resinous substance. The time sufficient for ordinary vesselssuch as basins and the like I have found to be from one to ten minutes; but for thicker or more solid articles more time may be required. After the article has been withdrawn from the bath the oil which isupon the surface penetrates the interior. The article is then submitted, in free contact with the air, to a degree of heat sufficient to convert the oil into a resinous solid. The temperature specified above-270 Fahrenheithas been found well suited to the purpose, and in twelve hours (more or less) the thickened oil is converted into a solid throughout-theinteriorof the paper or paper-pulp article. To secure the best results I repeat the operation above described.

After removing the article from the oven, and

while still hot, I plunge itagain into the thickened oil bath, allowing it to remain one or two minutes. It is then removed and allowed to drip, after which it is returned to the oven and heated to the same temperature as before. I subject the article to the alternate bath and heat from one to four times, according to the thickness and porosity of the material, the

thicker and more porous bodies requiring a greater number of the baths and beatings.

By the treatment above described the porous, flexible, slightly-elastic paper-stock is converted into a substance capable of resisting the action of water, (hot or cold,) of steam, carbonates of the alkalies, alcohol, or any of the substances to which such vessels are liable to be exposed. The article differs from the japanned or painted articles of paper in this, that the change is not of the surface simply, but throughout the body. Its elasticity is increased, and it can be readily filed, bored, or planed. When broken by violence its fracture is even or conchoidal, resembling that ofearthenware. It is sufficiently hard to resist ordinary scratching, takes a good polish, and may be painted, enameled, japanned, or lacquered.

I The pores are completely filled, and the vegetable fibers are thoroughly cemented by the tough elastic resin contained in the oil or produced therefrom.

For greater hardness or toughness, various resins and gumslike copal and caoutchoucmay be dissolved and added to the thickened oil without materially changing the general nature of the process or its product. When the liquid has become too thick for penetrating the pores it may be thinned by turpentine or ordinary linseed-oil.

In order to facilitate the induration ot' the article after it is charged with the linseed-oil, l introduce any of the metallic oxides or other soealleddriersinto the pulp, orinto the fibrous ware during its formation. The amount of these substances thus introduced into the pulp or ware should be proportioned to the amount of linseed-oil to be absorbed by the article, the proportion required to a given amount of oil being well known.

I may also use hydrostaticor pneumatic pressure to force the thickened oil into the pores of the fibrous material previous to its induration, and I may use also an air-pump to exhaust the air from the fibrous material in order that the hot thickened oil afterward applied may readily penetrate it. The wares or other articles formed of paper or paper-gulp and indurated as described may be covered by wood "eneers. By this means artificial boards may be made having the ordinary finished appearance of fine woods and of great strength, arising from the indurated paper or paper-pulp.

articles in thickened linseed-oil, or oil and gums, at substantially the temperature specified, and then exposing said articles to air and like temperature, substantially as set forth.

2. The described article of paper or paperpulp, having its pores filled with hardened linseed-oil, or linseed-oil with a proportion of gums, substantially as set forth.

In testimony whereofI have signed my name to this specification in the presence of two subscribing witnesses.

HENRY GARMIOHAEL.

Witnesses SAMUEL WING, MARY U. Mnnonnn. 

